NOV 22 iM 



The "Sexual Season" of Mammals and the 

 Relation of the " Pro-oestrum " to Menstruation. 



By 



Walter Hcape, M.A., 



Trinity College, Cambridge. 



Contents. 



Introduction 



The sexual season of male mammals 

 The breeding season of female mammals 

 The sexual season of female mammals 

 The periodicity of the sexual season i 



absence of the male 

 The duration of the sexual season in poljcestrou.^ mammals in the ab 



sence of the male . 

 The duration of the Oistrus in mouccst 



in the absence of the male 

 The effect of maternal influences on the 

 The pro-CEstrum 

 The period of oestrus 

 Summary and conclusion 

 Literature 



monoesirous mammals in the 



ous and polyoestrous mammals 

 sexual season and on cestrus 



PAGE 



1 



11 

 13 



If. 



21 



25 



'10 

 42 

 45 

 54 

 56 

 66 



Introduction. 



The following paper is concerned with certain phenomena 

 which affect reproduction and which occur in female mammals 

 prior to the fertilisation of the ovum. 



The times of propagation of the species and the behaviour 

 of many female mammals during certain portions of the 



VOL. 44, PART 1. NEW SERIES. A 



